1. Field of the Invention
The present invention relates to camera technologies and more particularly, although not exclusively, to technologies for camera bodies, interchangeable lens, and camera systems configured using such camera bodies and interchangeable lens.
2. Description of the Related Art
Conventionally several camera systems are known having communication to the camera body about an interchangeable lens.
For example, conventionally a camera system is known in which information about the interchangeable lens is transmitted to the camera body, which controls the interchangeable lens by sending and receiving a command for driving a focusing lens and a diaphragm of the interchangeable lens based on the transmitted information.
In these camera systems, it becomes impossible to continue a normal photographing operation in a case where a failure occurs in the interchangeable lens, as well as in the case of failure in the camera body.
In such a case, usually, a message indicating the failure is displayed and the camera operation is shifted to a photographing prohibition mode (release lock).
However, with respect to the failures related to the interchangeable lens, there are failures that adversely and critically affect the photographing as well as failures that affect the photographing to a relatively small degree.
In this regard, if the photographing is prohibited (release is locked) even in the case of the failure that affects the photographing to a relatively small degree, an opportunity for photographing a good scene is missed.
In order to solve the above problem, Japanese Patent Application Laid-Open No. 11-084445 discusses a camera that allows the photographing to continue without prohibiting the photographing (without the release lock) even when the failure occurs in an image stabilization system.
Further, Japanese Patent Application Laid-Open No. 11-084445 discusses a method for suppressing an image deterioration due to a camera shake to a minimum by changing an operation of the camera when the image stabilization system fails.
Japanese Patent Application Laid-Open No. 11-084445 describes that the release lock is not actuated when the image stabilization system fails.
However, the release lock is actuated in the case of other failures.
Besides, Japanese Patent Application Laid-Open No. 11-084445 does not refer to problems that occur in relation to the single-lens reflex camera system configured of the interchangeable lens and the camera body.
The camera system enables sending and receiving the information related to the failure in the interchangeable lens by defining a new communication command. However, some conventional camera bodies and interchangeable lens cannot deal with the new communication command.
Therefore, a demand has grown for the interchangeable lens that can operate without a failure even when it is combined with the camera body that cannot deal with the new communication command and also for the camera body that can operate without a failure even when it is combined with the interchangeable lens that cannot deal with the new communication command.